Zotero is a free citation management system that helps you locate, organize and store bibliographic data. Zotero works with web browsers, a web "bookmarklet" to grab citation details from websites and a desktop application. Zotero integrates with Microsoft Office Word (and potentially other word processing systems) to assist you, while you are writing research papers, manuscripts and grant proposals, in inserting in-text citations and generating the resulting reference lists. Your Zotero database can be organized into folders and there are robust sharing and social networking capabilities.
One of the truly amazing features of Zotero is its ability to extract bibliographic data from PDFs that you import into your Zotero desktop application. If you have already saved PDFs on your computer, this is the easiest way of getting those citation details into Zotero: drag and drop the PDFs into Zotero and the system will search for the bibliographic details and add that content to your database.
Zotero allows you to store up to 300 MB of data. If you need more storage space or want to access additional capabilities, more capacity is available with a personal subscription.
Zotero recommends several third-party app for mobile phone and tablets. Check this Zotero Mobile page for details (https://www.zotero.org/support/
If you are interested in using Zotero to its fullest, spend some time with these detailed tutorials and guides so that you can become aware of all the ways in which Zotero can assist with making your research continuum more efficient -- a process that starts with your initial research and concludes with citation formatting within your final research projects.
The University of Albany Libraries have put together an excellent, detailed guide to Zotero. Check it out! (http://libguides.library.albany.edu/content.php?pid=607199&sid=5013402